Abstract
Chemical mitochondrial uncouplers are lipophilic weak acids that increase proton transport into the mitochondrial matrix via a pathway independent of ATP synthase, thereby uncoupling nutrient oxidation from ATP production. These molecules enable determination of maximal cellular respiration and have antioxidant effects that protect from ischemia-reperfusion injury. However, the most widely used proton transporter uncouplers have off-target activity that lead to a range of undesired effects including plasma membrane depolarization, mitochondrial inhibition, and cytotoxicity. To identify new mitochondrial uncouplers that lack off-target activity at the plasma membrane, we screened a small molecule chemical library. Herein we report the identification and validation of a novel mitochondrial protonophore uncoupler (2-fluorophenyl){6-[(2-fluorophenyl)amino](1,2,5-oxadiazolo[3,4-e]pyrazin-5-yl)}amine, named BAM15, that does not depolarize the plasma membrane and protects mice from acute renal ischemic-reperfusion injury. Thus, BAM15 represents a reliable new tool for the analysis of cellular bioenergetic function that has therapeutic potential by altering mitochondrial function in vivo.